Most oil producing subterranean formations are characterized by pressurized gas. In some parts of the work hydrocarbon bearing formations have pressures sufficient to force liquid hydrocarbons (crude oil) to the earth's surface. In other parts of the world, the gas pressure is not sufficient to force liquid hydrocarbons to the earth's surface. However, in such formations, the presence of gas is nevertheless important since in many formations a gas drive is required to move liquid hydrocarbons from within the formation to the site of a producing well or wells.
As crude oil is extracted from a subterranean reservoir, the reservoir gas pressure decreases. As the gas pressure decreases, crude oil production rates usually fall. For these and other reasons, it has been found desirable in producing many subterranean formations to maintain gas pressure within the formations.
The characteristics of gas injected into a well can be critical. Free oxygen contained in injected gas can cause plugging of formations. Further free oxygen can result in bacteria growth that can plug a producing formation, and corrode tubulars in the producing well.
Ideally, gas injected into a reservoir to augment the production of liquid hydrocarbons should be oxygen-free. Therefore, when treating gas prior to injection, a most important step is to remove substantially all free oxygen.
The present invention provides a process for generating substantially oxygen-free exhaust gas that is particularly useful for injection into hydrocarbon bearing formations.
Examples of the use of exhaust gas from an engine for industrial purposes and examples of the use of exhaust gas to augment liquid hydrocarbon production are found in the following United States patents:
U.S.PAT. NO.INVENTOR(S)TITLE1,868,755MountDehydrator1,945,407Adair et al.Process of Purifying Gases2,240,550Conlon, Jr.Method of Retuning Gas to Gas-ProducingFormations2,825,408WatsonOil Recovery By Subsurface ThermalProcessing3,004,601BodineMethod and Apparatus for Augmenting OilRecovery from Wells by Refrigeration3,100,528Plummer, et al.Method for Using Inert Gas3,137,344WiemerMinimizing Loss of Driving Fluids inSecondary Recovery3,381,523NettlesMethod and Apparatus for Supplying GasUnder Pressure3,653,438WagnerMethod of Recovery of Petroleum Deposits3,908,762RedfordMethod for Establishing CommunicationPath in viscous Petroleum-ContainingFormations Including Tar Sand Deposits forUse in Oil Recovery Operations4,324,291Wong et al.Viscous Oil Recovery Method4,325,432HenryMethod of Oil Recovery4,533,374HaagMethod for Reducing Air Pollution4,546,829Martin et al.Enhanced Oil Recovery Process4,593,763BurkeCarbon Dioxide Well Injection Method4,891,939BrighentiSystem for the Cryogenic Processing andStorage of Combustion Products of HeatEngines5,232,049Christiansen,Sequentially flooding a Subterraneanet al.Hydrocarbon-Bearing Formation with aRepeating Cycle of Immiscible DisplacementGases5,988,280Crawford et al.Use of Engine Heat in Treating a Well Bore6,039,116Stevenson et al.Oil and Gas Production with Periodic GasInjection